Alloy



Patented Mar. 29, 1932 JOSEPH C. R. STONE, 0F BELMONT, MASSACHUSETTSALLOY No Drawing.

My invention relates to improvements in alloys-of the kind disclosed inmy United States Patent No. 1,442,742, issued to me January 16, 1923.The present application is a continuation part of my pending applica-.tion SerialNo. 450,593, filed May .7, 1930.

The present invention has among its objects the provision of ahomogeneous, malleable and ductile, acid-resistant alloy which may bereadily and economically attenuated by a millprocess of drawing orrolling.

The alloy according to the present invention consists essentially ofcopper and nickel with other materials, preferably tin and lead, toimpart thev desired chemical and physical properties. As a typical alloyaccording to the invention the same may consist of by weight about 70%copper, 28% nickel, 1.5%.tin, and 0.5% lead.

In the practice of the invention the tin 31111 lead may be first alloyedin the proportions mentioned, and this intermediate alloy then alloyedwith copper and nickel, say by use of a suitable electric furnace orplacing the substances in a graphite crucible lined with refractory clayand bringing them to the melting point. of the most refractory metal.

- Preferably, the crucible will be first raised to a white heat and themetals then be placed therein in the order of their specific gravities,that is to say, the tin-lead intermediate alloy in the bottom of thecrucible and the copper and nickel above it in the order named, afterwhich the contents of the crucible may be brought to about 2650 F.,causing the substances to melt and alloy. Conveniently,in makingthealloy about 0.5% of manganese may be added, say inthe form -of 21.30%manganese copper alloy to serve as an antisoxidant, which. manganesewill be sub-,

stantially entirely dissipated during the alloying operation.

Preferably, the alloy is free from carbon if it is intend-ed that thealloy shall be worked. Carbon is not particularly objectionable when thealloy is to be employed merely for castings, but when it is to be workedbest results will be secured when the carbon content is below,y0.08% ofthe alloy. Conveniently, the melt may be superheated Application filedJune 12,

1931. Serial N0. 544,037.

by raising its temperature to burn out the carbon, say, for example,when the constituents are melted in a crucible as above described, byincreasing the draft to raise the temperature of the melt-to say about3000 F. and maintaining it at that temperature for one or two mlnutesbefore pouring. The presence of certain other metals and metaloids'suchas,

for example, phosphorous, is to be avoided if best results are to besecured. Phosphorous, 0

for example, will render the alloy unhomogeneous after annealing, andwill destroy materially its acid resisting properties.

Preferably, the ingot is cast in a so-called snap mold, that is to say,a mold which has all corners rounded and is split, for example, along aplane which includes its axis, so as to prevent the effects of coolingthe liquid metal at sharp. corners, which latter would act to cause anon-uniform structure of the ingot resulting in checks in the sheets,wires, tubes, or the like formed therefrom. Preferably the metal ispoured from thecrucible into the mold at a slightly lower temperaturethan the alloying temperature, for example, it

may be poured at about 2350" E, which lower temperature may be securedby pouring the metal in a thin stream into the mold.

I have found'that ingots prepared as above may be cold rolled or drawnby the usual mill 30 processes without annealing between the successivedrawing or rolling operations. Pref-" erably in attenuating the ingot itis first reduced a material amount, say at least 30%,

and then rolled or drawn by successive steps inches thick withoutannealing. This product may be readily annealed, say by heating it toabout 1500 F. and permitting itto cool at room temperature, to produce aproduct which has a hardness of only about B 32 Rockwell, that 15 tosay, a metal about as soft as tin. 1 i

' I have found that the alloy, the tubes, plates, wires, and the likeformed of the alloy, above described may be worked either cold or hot,and can be readily welded, the alloy also- 106 having the desiredproperty that it may be hardened by heating it and then allowing it tocool, as for example, the material above described may be raised fromabout B 32 Rockwell to about 13 9O Rockwell by heating it to 1500 F. andallowing it to cool slowly, say by packing it in line. The temperatureto which the material is heated is however somewhat critical, andconveniently may be any temperature from 1300 F. to 1350 F. i

The property of the alloy just mentioned makes it particularly usefulfor fabricating plates for supporting false teeth. For example, ilypressed to conform with the hardened cast impressions of the mouth so asto form the plate for supporting the false teeth. This plate, then,according to the common practice in dentistry, will be coated withrubber compound which may be raised to the vul'canizing temperature ofsay 1380 F. and slowly allowed to cool, and at the end of the coolingoperation the plates, for example, will have a hardness of about B 90Rockwell, which in common parlance is glass hard.

As explaining some ofthe properties imparted to the metal, applicant hasfound that when the alloy is prepared as above described the lead is notin solution in the basic alloy of copper, nickel and tin. This, it isbelieved,

' acts to render the alloy readily workable, the

lead in efiect servin as a lubricant between the particles of the asicalloy.

As explaining the acid resisting property of the alloy, it is known thatin the electromotive series of elements the four essential metalsentering into the alloy have potentia values as follows:

Cu+ 42 Ni20 -Sn-10 Pb12 The relation of these potential values is suchthat the copper balances the remaining constituents, producing in efiYect what would be zero valence in an element rendering it acid resistant.

Applicant has found, however, that the above result will not be secured,or a homoa sheet of the soft alloy may be read-' crocking, that is tosay, soil articles in contact with it, provided in each given case thelea-d content does not exceed the tin content. It will therefore beobserved, that with the range of copper and nickel defined, to secureall the desired properties of the improved alloy the range of tin isabout 0.5 to 2%, the range of lead about 0.04 to 1.5%, and the range ofthe ratio of tin to lead about 12:1 to 1:1.

If desired, small percentages of materials other than those abovementioned may be incorporated into the alloy for imparting desiredspecial characteristics without altering the characteristic propertiesof the alloy.

Claims:

1. Alloys containing by weight approximately from 17 to 35% nickel, 0.5to 2% tin, 0.04 to 1.5% lead, with the balance approximately all copper,the amount of lead in each particular instance not exceeding the amountof tin.

2. Alloys containing by weight approximately from 17 to 35% nickel, 0.5to 2% tin, 0.04; to 1.5% lead, with the balance approximately allcopper, the amount of lead in each particular instance being at least1/12 the amount of tin.

3. Alloys containing by weight approximately from 17 to 35% nickel, 0.5to 2% tin, 0.04to 1.5% lead, with the balance approximately all copper,the amount of lead in each particular instance being at least 1/12 theamount of tin but not exceeding the amount of tin.

4. An alloy containing by weight approximately copper, 28% nickel, 1 5%tin, and lead.

In testimony whereof, I have signed my name to this specification.

JOSEPH C. R. STONE.

geneous alloy produced, with the lead not in solution, unless there arepresent at least about 0.5% tin, at least about 0.04% lead, and at leastabout 2.5% nickel, and unless the amountof lead present is more than1/12 the amount of tin. that with the nickel content of the alloybetween 17 and 35%, if the tin content does not exceed about 2% and thelead content does not exceed about 1.5%, the alloy, when the balance issubstantially all copper, will be malleable and ductile. can be coldrolled or drawn by usual mill processes without annealing between therolling or drawing steps, is

5 age hardening, and will not exhibit so-called Applicant has alsofound,

CERTIFICATE OF CORRECTION.

PatentNo. 1,851,218. 1 y Granted March 29 1932, to

. JOSEPH C. R. STONE.

- h It is hereby certified that error *appears in the printedspecification of the above numbered patent requiring'co'rrection asfoilows: Page 2., line ,7, for the wo'rd "'line" read lime; andthat theeaitl LettersPatent should be read with this correction therein that thesame may conform, to the record of the case in thePatent Office.

---Sig ned and sealed this 3rdday bf may, A. n. 1932.

K v J- -MOQI'G, (Seal) I 1 Acting Commissioner of Patents.

